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A284670
Exponents of powers of 5 that contain all ten decimal digits.
3
19, 22, 26, 27, 28, 29, 31, 34, 35, 37, 39, 40, 41, 49, 50, 51, 52, 56, 57, 59, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104
OFFSET
1,1
COMMENTS
It is conjectured that a(n) = n + 40 for n > 25.
LINKS
EXAMPLE
5^19 = 19073486328125, which contains two 1's, two 2's, two 3's, one 4, one 5, one 6, one 7, two 8's, one 9 and one 0, so 19 is in the sequence.
MATHEMATICA
Select[Range[110], Union[IntegerDigits[5^#]] == Range[0, 9] &] (* Indranil Ghosh, Apr 01 2017 *)
PROG
(PARI) isok(n) = #vecsort(digits(5^n), , 8) == 10; \\ Michel Marcus, Apr 01 2017
(Python)
from sympy.ntheory.factor_ import digits
r10 = set(range(10))
print([n for n in range(1, 111) if set(sorted(digits(5**n)[1:])) == r10]) # Indranil Ghosh, Apr 01 2017
CROSSREFS
Cf. A130694 (k=2), A236673 (k=3), this sequence (k=5).
Sequence in context: A050714 A113868 A056025 * A099954 A335347 A374465
KEYWORD
nonn,base
AUTHOR
Seiichi Manyama, Apr 01 2017
STATUS
approved